This invention relates to a yielding column for use in mines or structures.
Yielding columns are used in mines to provide indications of roof movement possibly leading to roof failure, while supporting the roof. A portion of the column is designed to provide a visible indication of yielding at a load somewhat below the ultimate strength of the column. A good column absorbs a lot of strain before it fails. FIG. 6 shows the characteristics of various roof-supporting arrangements. Wood cribs are excellent in this regard, as they have a long, flat stress-strain curve.
An object of the invention is provide a yielding column providing an improved visible indication of load indicative of potential roof failure.
Another object is to provide a support having a broad stress-strain curve.
These and other objects are attained by a yielding column as described below.